Terminology

The term limy bile syndrome is reserved for cases with biliary symptoms 2, usually resulting from associated biliary tract disease, and not from the limy bile in the gallbladder itself 3.

Epidemiology

Limy bile is a rare finding, with a prevalence of ~1% (range 0.1-1.7%) in patients that underwent biliary lithiasis surgery 4. Women are more frequently affected than men 3.

The disorder can occur in any age group, although patients over 40 years of age are most commonly affected 5.

There is a high association with biliary lithiasis 6,8 and chronic cholecystitis7. Limy bile rarely migrates into the cystic and common bile ducts 6.

Clinical presentation

Limy bile may be an incidental finding 2 on X-ray or unenhanced abdominal scans performed for other reasons.

Relevant symptoms are those of cholestasis, e.g. right upper quadrant tenderness or jaundice, especially in those patients with an already known history of biliary disease 6.

Pathology

Although the typical constitution of calcium milk is well known to be an inadequate concentration of calcium carbonate mixed with calcium phosphate and/or calcium bilirubinate 7, the exact pathophysiological mechanism as to its formation is not well understood.

Radiographic features

A milk of calcium gallbladder is highly radiodense on standard x-rays and CT 6. The density of calcium milk on radiographic studies and CT depends of the proportional presence of calcium carbonate 7 .

A calcium-fluid level is usually seen on standing X-rays and CT due to its high relative weight, comparable to that of gallbladder sludge, calcium milk is found in the dependent portion of the gallbladder.

Plain radiograph

The so-called exclamation sign on standard radiography is pathognomonic for the associated presence of calcium milk in the common bile duct 9.

CT

Unenhanced CT much better appreciates the presence of any associated gallstones and the may or may not confirm the presence of calcium milk or stones in the distal bile ducts 7. Moreover, CT allows to assess for chronic cholecystitis and gallbladder hydrops.

Ultrasound

Ultrasound is nonspecific for differentiating gallbladder sludge from limy bile 4 - in both cases, it will reveal the presence of a hyperechoic and heterogeneous substance dependently in the gallbladder.

MRI

MRI probably has no added value in the diagnosis of limy bile; MRCP however has a high sensitivity and specificity in detecting associated obstructive biliary tract pathology.